The Lazarus IDE is a stable and feature rich visual programming environment for the FreePascal Compiler. It supports the creation of self-standing graphical and console applications and runs on Linux, FreeBSD, MacOSX and Windows.

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notes :
1. during testing FP, error occured due to libtinfo.so.5 not found, link is made to libncurses.so, link also created to libtinfo.so

cross-platform, libraries mainly aimed at video game and multimedia programming. They handle common, low-level tasks such as creating windows, accepting user input, loading data, drawing images, playing sounds, etc. and generally abstracting away the underlying platform. However, Allegro is not a game engine: you are free to design and structure your program as you like.
Allegro 4

Allegro 4 is the classic library, whose API is backwards compatible all the way back to Allegro 2.0 for DOS/DJGPP (1996). It is no longer actively developed, but we still apply patches sent to us by contributors, mainly to fix minor bugs. Every so often we will make new releases.

Allegro.pas is a wrapper to allow Pascal language to use the Allegro game programming library, a portable library mainly aimed at video game and multimedia programming written in a mixture of C and assembler.

Allegro.pas allows you to use sprites, play sound and music, draw directly on the screen or on any-size memory bitmaps, get user input from keyboard, joystick and/or mouse, create 3D graphics, define a GUI and almost anything you need to create your own games. And you can do it in good old Pascal or the modern Object Pascal. Also, if you do it the right way, your program will run in Windows and Linux with few or not changes!

source:
allegro.pas-4.4.4-src-pas.tar.bz2
allegro-4.4.2.tar.gz

both compiled in 528-2, allegro.pas is compiled at root dir using fix.sh then compressed as it is.
Allegro is packaged as sfs
size 8Mb

You can copy the Allegro.pas library to the FPC's unit subdirectory so it will be available to all your projects without need to reconfigure it or add command options to the compilation line.

First localize where FPC has the RTL units:

On Windows systems it should be inside the directory where you installed FPC or Lazarus. If you installed Lazarus there should be a subdirectory named “fpc”.
On GNU/Linux systems a common place is the /usr/share/lib subdirectory.

In any case you should look for a subdirectory named fpc/<version_number>/units/i386/ or similar (<version_number> is the version of your FPC compiler).

Now create a subdirectory named allegro.pas and copy the contents of the lib subdirectory (may be you'll need administrator permissions to do this).